Method of and means for assembling wingshafts and abutments in rotary fluid pressure devices



Oct. 11, 1966 w. H. WESSE R ASSEMB I METHOD OF AND MEAN L ETAL. 3,277 6WINGSHA AND ABUTMEN L NG IN R0 Y FLUID PRESSURE DEVI Filed Sept. 17,

- INVENTO Wa//@r filVsssi/ I 0 4 A9 EObQP/EIe/hy 13y ATTORNEYS 3,277,796h/IE'IHUD OF AND MEANS FUR ASSEMBLING WINGSHAFTS AND AEUTMENTS IN R-IARY FLUID PRESSURE DEVICES Walter I. Wessel and Robert E. King, OrchardPark, NIL, assignors to ll-lloudaille Industries, Inc., Buffalo, N.Y., acorporation of Michigan Filed Sept. 17, 1963, Ser. No. 309,525 20Claims. (Cl. 92-125) This invention relates to improvements in rotaryfluid pressure devices, and more particularly concerns an improvedmethod of and means for assembling into the housings of such devices thewingshafts and abutments having pressure seals.

In order to avoid leakage past the abutments and the wingshafts inrotary fluid pressure devices such as rotary hydraulic actuators,motors, and the like, pressure seals are mounted in the edges thereof.Thus, a pressure seal is mounted in each wingshaft vane to engage withthe opposing bore surface of the generally ring-shaped housing body andthe end walls or caps defining the working chamber space within theunit. A similar pressure seal is mounted in each abutment to contact theopposing surfaces of the housing.

Due to the necessarily close tolerances between the' opposing matingsurfaces of the wingshaft vanes and of the abutments and the bore of thehousing, a serious problem is encountered when the wingshaft andabutment or abutments are axially assembled, due to the necessity ofcompressing the pressure seals to clear into the housing bore. Commonlythis has been effected by placing shim stock, that is, very thin toughsheet metal, protectively between the seals and the housing boresurface. However, this is a time-consuming expedient and the seals arequite often damaged when the tightly pressed shims are removed afterassembly has been completed.

It is, accordingly, an important object of the present invention toprovide a new and improved method of and means for assembling pressureseal equipped wingshafts and 'abutments into the housing bores of thefluid pressure devices in a manner requiring no substantial compressionof the seals until assembly is completed.

Another object of the invention is to provide a method of and means forassembling pressure sealed wingshafts and abutments in the bores offluid pressure device housings without any substantial compression ofthe seals until after assembly has been completed, whereafter placing ofthe seals under compression between the wingshaft and abutment with thehousing bore Wall in each instance is easily and efficientlyaccomplished without danger of damaging the seals.

A further object of the invention is to provide a new, simple, efficientmethod of assembling pressure sealed wingshafts and abut-ments withhydraulic rotary pressure devices and simple and highly efficient meansfor practicing the method.

According to the general features of the invention, assembly is effectedbetween parts having mating interface engagement With a pressure sealtherebetween by providing a ramp-sided groove in one of the parts andassembling the parts in a manner to introduce longitudinally into thegroove a projecting portion of the compressible pressure seal mounted ina recess in the other part, whereafter the parts are relatively shiftedlaterally relative to the groove to ease the projecting seal portionacross the groove ramp and thereby compress it into the recess until thegroove has been cleared and it sealingly engages the interface of saidone part.

Other objects, features and advantages of the present invention will bereadily apparent from the following detailed description of a preferredembodiment thereof taken ited States Patent 0 "ice in conjunction withthe accompanying drawing, wherein:

FIGURE 1 is a plan view of a rotary fluid pressure device embodyingfeatures of the invention;

FIGURE 2 is a plan view similar to FIGURE 1 but showing the parts beingassembled;

FIGURE 3 is an enlarged fragmentary sectional detail view showing how apressure seal is adapted to be accommodated during assembly; and

FIGURE 4 is a similar enlarged fragmentary sectional detail View showingthe parts after assembly has been completed.

A typical rotary fluid device such as a rotary actuator, motor, and thelike, includes a housing comprising a body 5 (FIG. 1) defining acylindrical working chamber bore 7 closed at one end by an end wall 8and at the opposite end by a similar end wall (not shown), one or bothof the end walls being a removable cap or disk member attached to thehousing body by means such as bolts 9. Relatively rotatably mountedconcentrically within the working chamber is a wingshaft 1t having oneor more wing vanes 11 which cooperate with a corresponding number,namely, one or more, of abutments 12 to divide the Working chamber into*subchambers. Suitable means such as dowels I3 secure the abutmentsfixedly in place. As is well-known, the wingshaft vanes 11 haverespective outer edges having surfaces which mate with fairly closetolerance slidably in the bore 7. Similarly, the abutments 12 havesurfaces which mate with fairly close tolerance within the bore 7 andwith the perimeter of the wingshaft 10 between the vanes 11.

In order to seal the interfitting surfaces of the vanes 11 and thehousing, and the interfitting surfaces of the abutments 12 and thehousing and the wingshaft, pressure seals on the order of thosedisclosed and covered in Patent 3,021,822 issu-sed February 20, 1962,are employed. One such seal 14- is mounted in a suitable groove recess15 in each of the abutments 12. A similar seal 17 is mounted in a slotrecess 18 in each of the vanes 11. Desirably the seals 14 and 17 are inthe form of molded solid elastomer material having low coefficient offriction of which the moldable plastic polytetrafluorethylene,commercially available under the trademark Teflon, is desirable althoughnylon or a like material may also be used. For thrusting the seal stripsor rings 14 and 17 outwardly from their respective grooves or slots soas to effect a tight sealing engagement against the opposed housingsurfaces, pressure applying means such as rubber O-rings 19 (FIG. 3) aremounted behind the respective seal strips and normally act to thrust theassociated sealing strip partially out of its groove or slot.Substantial inward pressure is then required to displace the sealingstrip inwardly against and to effect deformation and displacement of thesolid pressure backing O-ring 19. As mentioned hereinbefore, this hascreated a substantial problem in effecting assembly of the wingshaft andabutments equipped with this type of pressure seal into the bore 7 ofthe housing.

According to the present invention, assembly of the wingshaft andabutments is easily and quickly effected without requiring eitherprecompression of the seal, nor any type of shimming. To this end, ashallow relatively large radius, open ended, inwardly opening,longitudinally extending ramp-sided groove Zil is provided in thesurface defining the bore '7 and of a depth to receive the expanded,outwardly projecting portion of the seal substantially freely andwithout any substantial pressure. Thereby, a free relative axialassembly of the seal carrying member and the housing is enabled,substantially into the relationship depicted in FIGURES 2 and 3. Then byrelative turning, shifting displacement of the seal carrying member andthe housing, substantially as indicated by directional arrows in FIGURE3 (which is representative of assembling either the seal 14 or the seal17), the gradual, low pitch ramp provided by the side of the groovegently and progressively eases and compresses the seal inwardly until itrides laterally onto the bore surface and full sealing relationship ofthe seal is attained, substantially as shown in FIGURE 4.

Where a single abutment and a single vane wingshaft are to be assembledin the housing, a single groove 20 may sulfice for effecting assembly ofboth of the seal carrying members, namely the single abutment and thesingle wingshaft vane. In such case, the seal carrying members areplaced in assembly with the housing successively.

In a multi-abutment and vane arrangement such as the dual abutment anddual vane arrangement depicted in FIGURES 1 and 2, at least a pair ofthe assembly grooves 20 at diametrically opposite points in the borewall surface are provided for simultaneously receiving diametricallyopposite seal members of the wingshaft vanes, for example. However, in amore convenient arrangement, the grooves 20 are provided in sets of twoadjacent spaced parallel grooves so spaced apart that all of theabutments and all of the wingshaft vanes can be assembled with thehousing simultaneously as a unit, substantially as depicted in FIGURE 2.Hence, the abutments 12 are assembled on diametrically opposite sides ofthe wingshaft alongside and in abutment with the respective vanes 1-1which thus serve as locating or orienting members for the abutments. Theassembly of wingshaft and abutments is then aligned with the housingbore 7 and with the seals 14 and 17 aligned with the respective sets ofassembly grooves 20. Relative torsional displacement of the wingshaftand the abutments then displaces the seals from the respective grooves20 and compresses the seals.

Whether a single groove is used or a pair of grooves in a set, locationof the groove or grooves is desirable in such relation to the securedposition of the adjacent abutment 1-2 as to be covered by the abutment,substantially as shown in FIGURES 1 and 4, so as to prevent reentry ofthe wingshaft seals into the grooves.

As a result, the wingshaft and abutment structures can be inserted intothe housing bore without danger of damaging the seals. Assembling of theparts is substantially expedited and requires no special skill ordelicate handling to avoid seal damage. Milling of the grooves 20 is anextremely simple machining operation which adds little to the initialcost of making the parts, and as a cost factor is greatly offset bysavings effected in not only the assembling operation but freedom fromseal damage and thus rejection rate of the completed units.

It will be understood that modifications and variations may be effectedwithout departing from the scope of the novel concepts of the presentinvention.

We claim as our invention:

1. A method of assembling parts having close interface engagement with apressure seal therebetween,

providing a ramp-sided groove in the interface surface of one of theparts,

assembling the parts by longitudinally introducing into the groove aprojecting portion of a compressible seal in a recess in the interfacesurface of the other part,

and thereafter relatively shifting the parts laterally relative to thegroove and thereby easing the projecting seal portion across the grooveramp and compressing it into the recess until the seal has cleared thegroove and sealingly engages the interface surface of said one part.

2. The method defined in claim 1, further characterized by forming thegroove on a surface of relatively large radius arc.

3. A method of assembling into the bore of a housing a part having asurface arranged to mate with the surface of the bore and wherein arecess in one of the surfaces mounts a longitudinal compressiblepressure seal engageable sealingly with the opposing surface inassembly,

forming a ramp-sided groove in said opposing surface, assembling saidpart and said housing by longitudinal relative movement with saidsurfaces slidably e11- gaged and with said seal aligned with said grooveso that the seal projects into the groove during the longitudinalrelative assembly movement,

and after the longitudinal assembly movement has been completedrelatively torsionally shifting said part and the housing and therebymoving the seal laterally across the groove ramp and compressing it intothe recess until the seal engages said opposing surface beyond thegroove.

4. A method of assembling a fluid pressure device comprising a housingdefining a bore surface and an abutment having a surface complementaryto and adapted to mate with the bore surface with one of the surfaceshaving a longitudinal recess mounting a compressible pressure seal whichnormally projects from the recess,

forming in the other surface a ramp-sided groove of a depth to receivethe seal without substantial compression, relatively longitudinallyassembling the abutment and the housing with the seal aligned with andprojecting into the groove,

and after longitudinal assembly has been effected relatively turning theabutment and housing until the seal has been laterally eased by thegroove ramp compressively into the recess and sealingly onto said othersurface.

5. A method of assembling a fluid pressure device comprising a housingdefining a bore surface and an abutment having a surface complementaryto and adapted to mate with the bore surface with the abutment surfacehaving a longitudinal recess mounting a compressible pressure seal whichnormally projects from the recess,

forming in the bore surface a ramp-sided open ended groove of a depth toreceive the seal Without substantial compression,

relatively longitudinally assembling the abutment and the housing withthe seal aligned with and projecting into the groove,

and after longitudinal assembly has been effected relatively turning theabutment and housing until the seal moving with the abutment has beenlaterally eased by the groove ramp compressively into the recess andsealingly onto said bore surface.

6. A method of assembling a fluid pressure device comprising a housingdefining a bore surface and a wingshaft including a vane surfacecomplementary to and adapted to mate with the bore surface with the vanesurface having a longitudinal recess mounting a compressible pressureseal which normally projects from the recess,

forming in the bore surface a ramp-sided open ended groove of a depth toreceive the seal without substantial compression,

relatively longitudinally assembling the vane and the housing with theseal aligned with and projecting into the groove,

and after longitudinal assembly has been effected relatively turning thevane and housing until the seal moving with the vane has been laterallyeased by the groove ramp compressively into the recess and sealinglyinto said bore surface.

7. A method of assembling a rotary fluid pressure device comprising ahousing having a bore surface defining a working chamber and abutmentand wingshaft structures in the chamber wherein the abutment isstationary and the wingshaft has a vane,

forming a pair of longitudinal ramp-sided grooves in the bore surface,

mounting longitudinal compressible pressure seals in surfaces of theabutment and wingshaft that are arranged to mate with the bore surface,

assembling the abutment and wingshaft within the housing by relativelongitudinal movement and with the seals aligned with and projectinginto the respective grooves, and after longitudinal assembly has beeneffected, relatively turning the abutment and wingshaft and the housingand laterally easing the seals along the groove ramps onto the boresurface.

8. The method of claim 7 characterized by forming the grooves in spacedrelation less than the width of the mating surface of the abutment andcovering the grooves with the abutment so that the wingshaft seal isprevented from entering the groove by which it was accommodated duringassembly of the parts.

9. A method of assembling abutment and wingshaft parts in a workingchamber of a housing defined by a bore surface and wherein the abutmentand the wingshaft have surfaces mating with the bore surface andprovided with respective recesses mounting compressible pressure sealsnormally projecting from the recesses,

forming spaced parallel ramp-sided grooves in the bore surface receptiveof the projecting seals,

assembling the abutment with the wingshaft,

aligning the abutment and the wingshaft within said bore and aligningthe seals with said grooves,

relatively longitudinally assembling the assembled abutment andwingshaft and the housing and longitudinally entering the projectingportions of the seals in said grooves,

and after said longitudinal assembly has been effected relativelyturning the abutment and wingshaft assembly and the housing and therebylaterally easing the seals along the groove ramps compressively into therecesses and sealingly onto the bore surface.

It). In a method of assembling a plurality of abutment-s and amulti-vane wingshaft in a working chamber of a housing defined by a boresurface and wherein the abutments and the wingshaft vanes. have surfacesto engage matingly with the bore surface and provided with longitudinalrecesses mounting compressible pressure seals normally projecting fromthe recesses,

forming in the bore surface a plurality of spaced parallellongitudinally extending ramp-sided grooves equal in number to thenumber of seals on all of the abutments and wingshaft vanes and sooriented as to receive all of the projecting portions of the sealssimultaneously,

assembling the abutments with the wingshaft,

aligning the assembled abutments and wingshaft with the chamber bore andaligning the projecting portions of the seals with the respectivegrooves,

relatively longitudinally assembling the assembled abutments andwingshaft and the housing to bring said mating surfaces into engagementwith the bore surface and disposing the projecting portions of the sealsin said grooves,

relatively turning the abutments and wingshaft in respect to the housingand thereby laterally moving the seals along the ramps and compressingthe seals into their respective recesses until the seals engagesealingly with the bore surface beyond the respective grooves,

and fixing the abutments in blocking relation to the grooves whereby thewingshaft can be rotated for full travel of the vanes in eitherdirection between the abutments without reentry of the seals thereofinto the assembly grooves.

11. An assembly of parts having interfaces engageable in close relationand including:

a ramp-sided groove in the interface surface of one of the parts,

a recess in the interface surface of the other of said parts havingtherein a compressible sea-l with a portion of the seal normallyprojecting from the recess,

said groove being receptive of the projecting portion of the seal bylongitudinally introducing such portion into the groove,

the ramp of the groove being adapted to ease the projecting portion ofthe seal thereacross and compress it into the recess upon relativeshifting of the parts laterally with respect to the groove until theseal 5 has cleared the groove,

the seal engaging the interface surface of said one part. 12. Anassembly as defined in claim 11 characterized in that the groove is on asurface of relatively large radius arc.

13. An assembly comprising a housing having a bore surface,

a part having a surface arranged to mate with the surface of the bore,

one of the surfaces having a longitudinally extending recess with alongitudinal compressible pressure seal mounted therein and engageablesealingly with the other and opposing surface in the assembly,

a ramp-sided groove in said opposing surface,

said groove being adapted for assembling the part within the housing bylongitudinal relative movement with said surfaces slida'bly engaged andthe seal aligned with the groove so that the seal projects into thegroove during the longitudinal relative assembly movement,

said part and housing being relatively turned with respect to the grooveand the seal laterally moved out of the groove by the ramp and beingcompressed into the recess and engaging said opposing surface sealinglybeyond the groove.

14. A fluid pressure device comprising a housing defining a boresurface,

an abutment having a surface complementary to and mating with the boresurface,

one of the surfaces having a longitudinal recess mounting a compressiblepressure seal which normally projects from the recess,

the other of said surfaces having a ramp-sided groove of a depth toreceive the seal without substantial compression during relativelongitudinal assembly of the abutment and the housing with the sealaligned with and projecting into the groove,

said groove being adapted after the abutment and the housing have beenlongitudinally assembled to laterally ease the seal compressively intothe recess incident to relative turning of the abutment and housing,

the seal engaging the other of said surfaces sealingly.

15. A fluid pressure device comprising a housing defining a boresurface,

an abutment having a surface complementary to and mating with the boresurface,

the abutment surface having a longitudinal recess mounting therein acompressible pressure seal which normally projects from the recess,

a ramp-sided open ended groove in the bore surface of a depth to receivethe seal Without substantial compression during relative longitudinalassembling of the abutment and the housing and with the seal alignedwith and projecting into the groove,

the groove ramp being adapted to laterally ease the seal compressivelyinto the recess and sealingly onto the bore surface during relativeturning of the abutment and housing after longitudinal assembly,

the seal engaging said bore surface sealingly.

16. A fluid pressure device comprising a housing defin- 5 ing a boresurface,

a wingshaft including a vane surface complementary to and mating withthe bore surface,

the vane surface having a longitudinal recess mounting therein acompressible pressure seal which normally projects from the recess,

a ramp-sided open ended groove in the bore surface of a depth to receivethe seal without substantial compression during relative longitudinalassembling of the vane and the housing and with the seal aligned withand projecting into the groove,

the groove ramp being adapted to laterally ease the seal compressivelyinto the recess and sealingly onto the bore surface during relativeturning of the vane surface and housing after longitudinal assembly,

the seal engaging said bore surface sealingly.

17. A rotary fluid pressure device comprising a housing having a boresurface defining a working chamber and abutment and wingshaft structuresin the chamber wherein the abutment is stationary and the wingshaft hasa vane,

a pair of longitudinal ramp-sided grooves in the bore surface,

longitudinal compressible pressure seals in surfaces of the abutment andwingshaft mating with the bore surface,

said grooves being so disposed that the abutment and wingshaft can beassembled with the housing by relative longitudinal movement and wit-hthe seals aligned with and projecting into the respective grooves,

the abutment and wingshaft being relatively displaced with respect tothe grooves with the seals laterally eased out of the grooves along thegroove ramps and engaging the bore surface.

13. The assembly of claim 17 characterized in that the grooves are inspaced relation less than the width of the mating surface of theabutment and substantially covered by the abutment so that the wingshaftseal is prevented from entering any groove in the rotary movements ofthe wingshaft in the working chamber.

19. A rotary fiuid pressure device including a housing having a boresurface defining a working chamber and abutment and wingshaft structuresin the working chamber having surfaces mating with the bore surface andprovided with respective recesses mounting compressible pressure sealsnormally projecting from the recesses,

said bore having parallel ramp-sided grooves receptive of the projectingseals, whereby the abutment and wingshaft assembled together are adaptedto be aligned with the working chamber bore and with the seals alignedwith the grooves and assembled into the working chamber bore by relativelongitudinal assembly movement with the projecting portions of the sealsin the grooves,

said abutment and wingshaft structures being turned relative to thegrooves and with the seals laterally eased from the grooves by thegroove ramps and under compression into the recesses and sealinglyengaging the bore surface.

20. A fluid pressure device comprising a plurality 1f abutments and amulti-vane wingshaft,

a housing having a working chamber therein defined by a bore surface andwith the abutments and wingshaft vanes provided with surfaces engagingmatingly with the bore surface,

said abutment and vane surfaces having longitudinal recesses mountingcompressible pressure seals normally projecting from the recesses,

said bore surface having therein a plurality of spaced parallellongitudinally extending ramp-sided grooves equal in number to thenumber of seals on all of the abutments and wingshaft vanes and sooriented as to receive all of the projecting portions of the sealssimultaneously when the abutments and wingshaft are longitudinallyassembled within the chamber simultaneously,

the seals being arranged to be compressed into their respective recessesby the groove ramps upon relative lateral turning of the abutments andwingshafts in the housing,

the seals engaging sealingly with the bore surface beyond the respectivegrooves,

the abutments being disposed in blocking relation to the grooves wherebythe wingshaft can be rotated for full travel of the vanes in eitherdirection between the abutments without reentry of the seals of thevanes into the assembly grooves,

and means fixing the abutments in said blocking relation.

References Cited by the Examiner UNITED STATES PATENTS 3,030,934 4/1962Herbst 2778l 3,215,046 11/1965 Drake 92-125 MARTIN P. SCHWADRON, PrimaryExaminer.

I. C. COHEN, Assistant Examiner.

1. A METHOD OF ASSEMBLING PARTS HAVING CLOSE INTERFACE ENGAGEMENT WITH APRESSURE SEAL THEREBETWEEN, PROVIDING A RAMP-SIDED GROOVE IN THEINTEFACE SURFACE OF ONE OF THE PARTS, ASSEMBLING THE PARTS BYLONGITUDINALLY INTRODUCING INTO THE GROOVE A PROJECTING PORTION OF ACOMPRESSIBLE SEAL IN A RECESS IN THE INTERFACE SURFACE OF THE OTHERPART, AND THEREAFTER RELATIVELY SHIFTING THE PARTS LATERALLY RELATIVE TOTHE GROOVE AND THEREBY EASING THE PROJECTING SEAL PORTION ACROSS THEGROOVE RAMP AND COMPRESSING IT INTO THE RECESS UNTIL THE SEAL HASCLEARED THE GROOVE AND SEALINGLY ENGAGES THE INTERFACE SURFACE OF SAIDONE PART.